From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761196AbXERDpZ (ORCPT ); Thu, 17 May 2007 23:45:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757087AbXERDpN (ORCPT ); Thu, 17 May 2007 23:45:13 -0400 Received: from haxent.com ([65.99.219.155]:2115 "EHLO haxent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756328AbXERDpM (ORCPT ); Thu, 17 May 2007 23:45:12 -0400 Message-ID: <464D2142.3070705@haxent.com.br> Date: Fri, 18 May 2007 00:45:06 -0300 From: Davi Arnaut MIME-Version: 1.0 To: Andrew Morton , Davide Libenzi , Linus Torvalds , Linux Kernel Mailing List Subject: [PATCH] timerfd/eventfd context lock doesn't protect against poll_wait Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, poll_wait() callback may modify the waitqueue without holding the context private lock. Signed-off-by: Davi E. M. Arnaut diff --git a/fs/eventfd.c b/fs/eventfd.c index 480e2b3..9c672be 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -50,7 +50,7 @@ int eventfd_signal(struct file *file, int n) n = (int) (ULLONG_MAX - ctx->count); ctx->count += n; if (waitqueue_active(&ctx->wqh)) - wake_up_locked(&ctx->wqh); + wake_up(&ctx->wqh); spin_unlock_irqrestore(&ctx->lock, flags); return n; @@ -98,7 +98,7 @@ static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, if (ucnt > 0) res = sizeof(ucnt); else if (!(file->f_flags & O_NONBLOCK)) { - __add_wait_queue(&ctx->wqh, &wait); + add_wait_queue(&ctx->wqh, &wait); for (res = 0;;) { set_current_state(TASK_INTERRUPTIBLE); if (ctx->count > 0) { @@ -114,13 +114,13 @@ static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, schedule(); spin_lock_irq(&ctx->lock); } - __remove_wait_queue(&ctx->wqh, &wait); + remove_wait_queue(&ctx->wqh, &wait); __set_current_state(TASK_RUNNING); } if (res > 0) { ctx->count = 0; if (waitqueue_active(&ctx->wqh)) - wake_up_locked(&ctx->wqh); + wake_up(&ctx->wqh); } spin_unlock_irq(&ctx->lock); if (res > 0 && put_user(ucnt, (__u64 __user *) buf)) @@ -148,7 +148,7 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c if (ULLONG_MAX - ctx->count > ucnt) res = sizeof(ucnt); else if (!(file->f_flags & O_NONBLOCK)) { - __add_wait_queue(&ctx->wqh, &wait); + add_wait_queue(&ctx->wqh, &wait); for (res = 0;;) { set_current_state(TASK_INTERRUPTIBLE); if (ULLONG_MAX - ctx->count > ucnt) { @@ -163,13 +163,13 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c schedule(); spin_lock_irq(&ctx->lock); } - __remove_wait_queue(&ctx->wqh, &wait); + remove_wait_queue(&ctx->wqh, &wait); __set_current_state(TASK_RUNNING); } if (res > 0) { ctx->count += ucnt; if (waitqueue_active(&ctx->wqh)) - wake_up_locked(&ctx->wqh); + wake_up(&ctx->wqh); } spin_unlock_irq(&ctx->lock); diff --git a/fs/timerfd.c b/fs/timerfd.c index e329e37..e48eae7 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -41,8 +41,8 @@ static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr) spin_lock_irqsave(&ctx->lock, flags); ctx->expired = 1; - wake_up_locked(&ctx->wqh); spin_unlock_irqrestore(&ctx->lock, flags); + wake_up(&ctx->wqh); return HRTIMER_NORESTART; } @@ -104,7 +104,7 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count, spin_lock_irq(&ctx->lock); res = -EAGAIN; if (!ctx->expired && !(file->f_flags & O_NONBLOCK)) { - __add_wait_queue(&ctx->wqh, &wait); + add_wait_queue(&ctx->wqh, &wait); for (res = 0;;) { set_current_state(TASK_INTERRUPTIBLE); if (ctx->expired) { @@ -119,7 +119,7 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count, schedule(); spin_lock_irq(&ctx->lock); } - __remove_wait_queue(&ctx->wqh, &wait); + remove_wait_queue(&ctx->wqh, &wait); __set_current_state(TASK_RUNNING); } if (ctx->expired) {